Ball screw and assembly method

Abstract

A diverter for a ball return of a ball screw configured for lifting in and lifting out balls from a ball channel between the spindle nut and the threaded spindle. The diverter is configured in one piece and has 3 functional units, specifically a positioning element, a deflection element having a spade-like lifting-out region and a diverting surface for balls out of or into the ball channel. All surfaces of the diverter that are provided for guidance of balls are configured as circumferentially open grooves (not closed in the manner of a tunnel). A method for assembling such a ball return includes providing two single-piece, structurally identical diverters; providing a pre-assembled module with a spindle nut and a threaded spindle, the spindle nut having two inwardly fitted apertures; inserting the diverters into the apertures; introducing balls; and securing the ball return by attaching a covering sleeve to the spindle nut.

The invention claimed is: 
     
       1. A ball return of a ball screw, the ball return comprising:
 a diverting channel and two structurally identical diverters configured for lifting in and lifting out balls from a ball channel between a spindle nut and a threaded spindle of the ball screw, each diverter comprising: 
 one piece having at least 2 functional regions or elements, including: 
 (i) a positioning element, configured to define an installation 
 position of the diverter, the positioning element has a substantially oval basic shape, and 
 (ii) a deflection element with a spade-shaped lifting-out region and a diverting surface for deflecting the balls out of or into the ball channel; 
 all surfaces of the diverter that are provided for the guidance of balls are configured as open grooves which are not circumferentially closed; and 
 wherein the positioning element is configured to terminates flush with a lateral surface of the spindle nut, 
 the diverters being configured to be inserted from outside into a lateral surface of the spindle nut such that the positioning elements terminate flush with the lateral surface of the spindle nut, wherein each of the diverting elements is configured to be inserted exclusively radially into the lateral surface at a right angle to a longitudinal axis of the ball screw. 
 
     
     
       2. The ball return as claimed in  claim 1 , wherein the positioning element has a height that is smaller than a thickness at a circumference of the spindle nut at an installation site. 
     
     
       3. The ball return as claimed in  claim 1 , wherein the positioning element transitions seamlessly into the deflection element. 
     
     
       4. The ball return as claimed in  claim 1 , wherein the diverter is an injection molded plastic workpiece. 
     
     
       5. The ball return as claimed in  claim 1 , wherein the diverter is configured for use as both an element for introducing and for lifting out balls from the ball channel. 
     
     
       6. The ball return as claimed in  claim 1 , wherein the open grooves, which are not circumferentially closed, have a free opening angle ϕ of at least 30° measured from groove edges to an operationally conventional position of one of the balls in the channel, oriented perpendicularly to a direction of movement of the ball. 
     
     
       7. The ball return as claimed in  claim 1 , wherein the diverting channel is configured as a trough or trench recessed in the lateral surface of the spindle nut. 
     
     
       8. The ball return as claimed in  claim 1 , wherein the diverting channel and the diverters are closable during assembly by a sleeve enclosing the spindle nut in a flush manner. 
     
     
       9. The ball return as claimed in  claim 1 , wherein the diverting channel is configured as a separate component constructed or placed on the lateral surface of the spindle nut. 
     
     
       10. A method for assembling a ball return of a ball screw, comprising the following steps:
 providing two single-piece, structurally identical diverters configured for lifting in and lifting out balls from a ball channel between a spindle nut and a threaded spindle of the ball screw, each diverter comprising: 
 one piece having at least 2 functional regions or elements, including: 
 (i) a positioning element, configured to define an installation 
 position of the diverter, the positioning element has a substantially oval basic shape, and 
 (ii) a deflection element with a spade-shaped lifting-out region and a diverting surface for deflecting the balls out of or into the ball channel; 
 all surfaces of the diverter that are provided for the guidance of balls are configured as open grooves which are not circumferentially closed; and 
 wherein the positioning element is configured to terminates flush with a lateral surface of the spindle nut; 
 providing a pre-assembled module including at least one spindle nut and a threaded spindle, the spindle nut having two radially inwardly directed apertures, contours of which are configured to receive the diverters, and a ball channel which also connects one of the apertures; 
 inserting the diverters into the apertures exclusively radially at a right angle to a longitudinal axis of the ball screw; 
 introducing a plurality of balls into the ball screw via the ball channel or one of the diverters; and 
 securing the ball return by attaching a covering sleeve to the spindle nut.